Koumac (French pronunciation: [kumak]) is a commune in the North Province of New Caledonia, an overseas territory of France in the Pacific Ocean.

On 5 January 1977 about 46% of the territory of Koumac was detached and became the commune of Poum.

It has good connections north and south by road, and several shops, industrial suppliers, and utilities.

Koumac Airport is located a couple kilometres north of the commune with regular flights to Nouméa.

Koumac has a tropical savanna climate (Köppen Aw), although there is still some rain in the dry season which peaks between July and October.